Free Function Theory Through Matrix Invariants
Free Function Theory Through Matrix Invariants
复制标题
通过矩阵不变量的自由函数理论
DOI:
10.4153/cjm-2015-055-7
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发表时间:
2014
期刊:
影响因子:
--
通讯作者:
S. Spenko
中科院分区:
文献类型:
--
作者:
I. Klep;S. Spenko
Abstract This paper concerns free function theory. Free maps are free analogs of analytic functions in several complex variables and are defined in terms of freely noncommuting variables. A function of $g$ noncommuting variables is a function on $g$ -tuples of square matrices of all sizes that respects direct sums and simultaneous conjugation. Examples of such maps include noncommutative polynomials, noncommutative rational functions, and convergent noncommutative power series. In sharp contrast to the existing literature in free analysis, this article investigates free maps with involution, free analogs of real analytic functions. To get a grip on these, techniques and tools from invariant theory are developed and applied to free analysis. Here is a sample of the results obtained. A characterization of polynomial free maps via properties of their finite-dimensional slices is presented and then used to establish power series expansions for analytic free maps about scalar and non-scalar points; the latter are series of generalized polynomials for which an invariant-theoretic characterization is given. Furthermore, an inverse and implicit function theorem for free maps with involution is obtained. Finally, with a selection of carefully chosen examples it is shown that free maps with involution do not exhibit strong rigidity properties enjoyed by their involution-free counterparts.
DOI:
10.4153/cmb-2017-044-4
发表时间:
2018
期刊:
Canadian Mathematical Bulletin
影响因子:
--
作者:
Agler, Jim;McCarthy, John
通讯作者:
McCarthy, John
影响因子:
1.3
作者:
Agler, Jim
通讯作者:
Agler, Jim